i7 875K: A More Affordable, Unlocked Version of an Intel Processor

Author

Oik Yusuf Araya

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Features Processors

July 3, 2010

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Unlocking the Potentials

An unlocked processor is destined for over clocking purposes, so we naturally bumped the speed up as high as we could. We also tested it in default condition, of course, to provide you with an estimation of how much more performance you can expect from the Core i7 875K.

This is the default base clock: multiplier ratio of the Core i7 875K

Our motherboard allows a multiplier increase of up to a whopping 62x, resuting in 8+ GHz frequency, though we seriously doubt if that would actually happen.

As for the over clocking effort, we first experimented with various settings across several parameters. Aside from increasing the multiplier value, we also tried over clocking the Core i7 875K by increasing the base clock as well as applying some combinations of both multiplier and baseclock increasements. To help with the stability, we also pumped a bit of extra voltage into the processor.

875K_4000_133x30 — 4 GHz, 30x133 MHz, QPI: 4,8 GHz, Memory: 1333 MHz

875K_4256_133x32 — 4.256 GHz, 32x133 MHz, QPI: 4,8 GHz, Memory: 1333 MHz

875K_3400_200x17 — 3,4 GHz, 17x200 MHz, QPI: 7,2 GHz, Memory: 2000 MHz

875K_4000_200x20 — 4 GHz, 20x200 MHz, QPI: 7,2 GHz, Memory: 2000 MHz

875K_4200_200x21 — 4,2 GHz, 21x200 MHz, QPI: 7,2 GHz, Memory: 2000 MHz

Using the Thermal Take Contact 29 HSF, we managed to increase the Intel Core i7 875K’s clock speed to 4256 MHz (32x 133MHz), a good 1.300 MHz above the original frequency. EIST and Turbo Boost technologies were disabled to maintain consistency of the processor’s speed. As a comparison, we brought along an overclocked Intel Core i7 930.